1. Field of the Invention
The invention relates to a headphone with two housings, comprising one right housing and one left housing, each of which are associated with the user""s ears. These housings contain acoustic baffles which have dynamic sound transducers, each of which comprises a tweeter and a mid/woofer disposed coaxially therewith.
2. Description of the Prior Art
Stereo headphones normally contain an arrangement of acoustic baffles at a center region of a housing of the headphones. This conventional arrangement has a design disadvantage because the auditory events produced thereby are perceived by a user to be localized in an upper part of the user""s head, with some differentiation in a rearwardly directed hemisphere. This means that auditory events or sounds intended to simulate a stage located in front of a user are not localized frontally during reproduction or the playing of music via a conventional stereo headphone. This conflicts with the normal human hearing sensation, explaining why much of the listening public refuses to use headphones because they sound unnatural.
In-head localization of auditory events is caused when using headphones that cause ear and body reflections during sound reception via headphones. However, in this case, perceived comb-filtered audio effects cannot be processed by the ear, since they are not supplied thereto.
This drawback can be overcome by mixing the missing comb-filtered audio effects into the signal supplied to the headphone. This necessitates very complex circuitry. In addition, to overcome this drawback, the headphones must be adapted to the individual ear of the user to achieve satisfactory frontal localization by the headphones.
The prior art establishes a design for headphones of a completely different nature for creating frontal localization by stereo headphones, as disclosed in European Patent EP 0484354 B1. According to this proposal, the headphones that produce comb-filtered audio effects needed for frontal localization contain a plurality of sound transducer systems in both headphone housings in a position shifted forward and down by predetermined amounts in the direction of sight. This position is compared with the conventional arrangement wherein sound transducer systems are in a central region on the outer envelope of the ears. Because of this relatively simple design the localization in the upper part of the head that was previously experienced is transformed into a hearing event that can be localized substantially horizontally toward the front.
Headphones working according to this principle for frontal localization of auditory events have proved effective in overcoming the drawbacks of the prior art. However, for small-sized headphones, such as headphones which rest on the ear as in the case of the Walkman(trademark) and similar devices, it is not as easy to arrange the acoustic baffles in a position shifted forward and down.
One object of the present invention is to overcome the above-mentioned disadvantage and to provide front localization with simple means, even for small headphones, without the use of electronics.
Another object of the invention is to provide a headphone with controllable localization of an auditory event.
Yet another object of the invention is to provide a surround headphone with frontal localization of the front channels and of a middle channel and localization of surround channels separated therefrom.
To achieve the foregoing objectives, the present invention provides a headphone that permits control of the localization of auditory events reproduced with the headphone by producing comb-filtered audio effects. This comb-filtering is generated by selective shadowing of the radiated sound, and is based on the frequency response of the reproduced sound. This comb-filtered effect can be achieved by using a headphone of small or ultra-small size, since the coaxial acoustic baffles are disposed in a conventional manner in the headphone and the control of the localization of the auditory event is achieved by selectively covering or damping regions of the mid/woofer and of the tweeter.
A stereo headphone for frontal localization of auditory events contains transmissive regions or shadowed regions of the acoustic baffles which are disposed so that the sound is selectively radiated downward. Hereby there is frontal localization in the same quality as with the first embodiment of inventor""s proposal to dispose acoustic baffles shifted forward and down compared with the conventional arrangement.
The invention also provides for a surround headphone having frontal localization of the front stereo middle channels and separate localization of the rear and side channels, such as the surround channels. Starting from the stereo headphone with frontal localization, a second set of acoustic baffles is disposed in a mirror image position in a horizontal plane relative to the first set of acoustic baffles on a horizontal plane relative to the user""s head. Thus, the surround channels can be localized separately from the stereo/middle channels. Nevertheless, this design represents an extremely simple expedient for effectively differentiating sound fields reproduced by headphones.